Therapeutically important cyclooxygenase-mediated unsaturated fatty acids oxidation stimulation in the isolated rabbit leukocytes during and after UV irradiation in the absence of Ca²⁺ in the incubation media was studied. It was shown that (1) photoinduced activation of the cyclooxygenase-dependent unsaturated fatty acids oxidation in the rabbit leukocytes is maximal after irradiation of the cells by UVC radiation in the dose 1,28 x 10² einstein/m² with following incubation during 60 min at 37 °C; (2) photoinduced activation of the cyclooxygenase-dependent unsaturated fatty acids oxidation in the rabbit leukocytes is accompanied by inhibition of these cells chemiluminescence responses to forbol-12-miristate-13-acetate stimulation.